In 2000, I went on vacation alone for the first time. The prospect of a week on Captiva Island, reading and swimming and reading again, was delicious. Of course, the dilemma was what to read: mysteries, literature, general fiction, essays, or something else. Who knew what I’d feel like reading on a given day? So I did what any reasonable person would do: I loaded up my suitcase with books and tucked some clothes in around them. At the Fort Myers airport, as I tried to lift my suitcase into a rental car, I found myself wishing there was an alternative to hauling a library around.